Trigger switch for actuating an alarm



Sept. 29', 1970 J. J. IMBURGIA I TRIGGER SWITCH FOR ACTUATING AN ALARMFiled June 4, 1969 44 FIG. 4

INVENTOR JOHN J. -|MBURGIA j ATTORNEY United States Patent US. Cl.20061.04 8 Claims ABSTRACT OF THE DISCLOSURE Two spaced electricalcontacts in the bottom of a housing are connected in circuit with analarm, which is energized when the contacts are bridged by a metal platethat is fastened intermediate its ends in the housing to a tensionspring, which normally urges it towards the contacts. The plate can bedrawn manually away from the contacts and releasably fastened to a capon the upper end of the housing by means including a plug adapted eitherto dissolve in water, or to melt in response to intense heat, thereby torelease the spring-loaded plate and permit it to reengage the electricalcontacts and to trigger the alarm.

The present invention relates to alarms and more particularly toapparatus for use in a household, store, or factory for actuating asignal in case of fire or high water.

Fire is always a constant danger to any dwelling, store, or factory. Ifthe building catches fire, water is poured into it to extinguish thefire. Where the building is protected by an automatic sprinkler system,the sprinkler system may be accidentally touched off; and, in any event,if there is an actual fire, the water from the sprinkler system will beadded to that poured into the structure by the firemen. Frequently, thewater is poured into the building at so great a rate that it isimpossible for it to drain off as fast as it is supplied. If the fire ison an upper floor of a building, the water, seeking an exit, may rundown to the floors below, causing water damage to any equipment,furniture, or other goods therein.

A primary object of this invention is to provide simple, reusable,easily-settable apparatus for actuating an alarm in event of fire orhigh water.

Another object of the invention is to provide apparatus which may beused to operate a drain or scupper to permit drainage of water from abuilding or any floor thereof if water exceeds a predetermined leveltherein.

Other objects of the invention will be apparent hereinafter from thespecification and from the recital of the appended claims, particularlywhen read in conjunction with the accompanying drawing.

In the drawing:

FIG. 1 is a front elevation of an alarm device constructed according toone embodiment of this invention, the device being shown in cockedcondition;

FIG. 2 is a diametral section through the device with parts shown inelevation;

FIG. 3 is a similar view to FIG. 1 but showing the device in trippedcondition;

FIG. 4 is a view similar to FIG. 2, but showing the device in trippedcondition, and additionally the manner in which the device may beconnected electrically to an alarm;

FIG. 5 is a fragmentary diametral sectional view of the trippingmechanism of a modification of the invention, particularly intended foruse as a burglar alarm; and

FIG. 6 is a fragmentary diametral sectional view showing another form oftripping mechanism for a burglar alarm built according to the invention.

Referring now to the drawing by numerals of reference, 10 denotes agenerally cup-shaped casing having its upper end closed by a cap 12. Cap12 has a cylindrical block 14 welded or riveted or otherwise secured toits inner face. This block has a pin 16 extending diametrally throughand having down-turned ends 18 at opposite ends projecting beyond theblock.

These ends 18 serve as detents, and are adapted to be passed throughholes 20 in a plate 22, to releasably lock plate 22 to cap 12. Theprojecting ends 18 of the pin 16 are passed through the holes 20 in theplate 22 and then the cap 12 is rotated through to lock the plate to thecap.

A coil tension spring 24 is secured at its upper end to the plate 20. Atits lower end this spring is secured to a disc 26 which is held to thebottom of casing 10 by a bolt 28, which passes through the bottom of thecasing, and by a nut 30 which threads onto the bolt externally of thecasing. Projecting into the casing through the bottom thereof are twoconductor rods 32 having headed inner terminal ends 34. Insulatingsleeves 36 surround the conductor rods. The rods project outside thebottom of the casing and electrical lead wires 38, 39 are secured inelectrically conductive contact with the projecting ends of the rods bynuts 40 which thread onto the externally projecting ends of the rods.

The line 38 is connected to one side of a battery 42. The other side ofthe battery is connected by a line 44 to one side of an electromagnet orother device housed in a casing 46 for operating the clapper 48 of abell 50. The other side of the electromagnet is connected to line 39.

The plate 22 is made of metal or other electrically conductive material.When it is in the position shown in FIG. 4 it bridges the heads 34 ofthe terminal rods 32, closing the circuit to the electromagnet which ishoused in the casing 46, and sounding the alarm.

Secured on the cap 12 is a tubular housing 52 in which a headed pin 54is mounted. This pin is constantly urged upwardly by a coil spring 56which is interposed between the head 58 of the pin 54 and a shoulderformed internally in the housing 52 adjacent the bottom of the housing.

The top of the housing has tangs 62 on it which are bent or spun over,to retain the pin 54 in the housing. In use, a readily heat-meltabledisc 60 is interposed between the head 58 of pin 54 and the tangs 62 ofthe housing if the device is to be used to operate a fire alarm, and awater soluble tablet is interposed between the head 58 of the pin andthe tangs if the device is to be used to open a scupper or drain todrain 01f high high water.

When the meltable disc or soluble tablet 60 is in place between the head58 of pin 54 and the tangs 62, the device can be cocked by removing cap12, inserting a hook into one of the holes 20 in plate 22, pulling theplate out of the casing 10 against the resistance of spring 24, thengrasping the plate 22 and releasing the hook, and inserting the ends 18of the pin 16 through the holes 20 in the plate, and rotating the cap 12until pin 54 snaps into a recess 64 in plate 22, thereby locking cap 12and plate 22 together and moving pins 18 out of registry with holes 20.The cap 12 is then replaced in the casing and rotated to wind up spring24. A screw 66 is then threaded into a hole in the periphery of cap 12to lock the device in its cocked position.

If the disc 60 is a heat-meltable disc, and a fire occurs in thebuilding in which the device has been installed, the disc will melt, thespring 56 will force the pin upwardly disengaging it from the recess 64in the plate 22. With the plate thus freed, the spring 24 will rotate itrelative to cap 12 which is held stationary by screw 66. As soon as theholes 20 in the plate register with the pin ends 18, the spring 24 willpull the plate 22 clear of the pin ends and 3 carry the plate into theposition shown in FIG. 4 where the plate bridges terminal heads 34-,closing the circuit to the alarm, to the scupper or drain or whatever itis that the device is wired to operate.

For a burglar alarm the tripping mechanism may be modified as shown inFIG. 5. Here the housing 72 has a pin 74 mounted in it which has acollar 75 intermediate its ends and a guide portion 76 of smallerdiameter than collar 75 and abutting the lower face of collar 75. Pin 74reciprocates rectilinearly in a guide sleeve 79 that is threaded intothe lower end of housing 72 and is guided in its reciprocating movementby guide portion 76. Interposed between the upper end 77 of housing 72and collar 75 is a coil spring 78, which urges thelower,'reduceddiameter portion 80 of pin 74 constantly toward engagementwith recess 64 in plate 22. A chain or the like 82, which is secured atone end in a hole 83 in the upper end of pin 74 connects pin 74 to adoor or a window of the building, which is to be protected by the alarmdevice.

This device is cocked in the same way as the device of FIGS. 1 to 4, andwhen in cocked position plate 22 is locked as above described. If aburglar opens a door or window to which chain 82 is secured, the pin 74will be retracted from hole 64 in plate 22, and spring 24 will revolvethe plate closing the circuit to the alarm as above described.

The device of FIG. 6 is similar to that of FIG. except that it comprisesa plunger 92 that reciprocates in housing 52. This plunger is adapted tobe forced outwardly of housing 52 by pressure of a spring 98, which isinterposed between the collar 95 on the plunger and the fitting 79 thatthreads into the bottom of housing 52. Plunger 97 is adapted to engageat its lower end in recess 64 in plate 22 to hold plate 22 againstrotation. A head 96 on the plunger engages against the back of apaintin-gor the underside of a typewriter, or other object that is to beprotected by the device. Spring 98 constantly presses plunger 92outwardly of casing 52; but is held in the position shown by the weightof the painting, which is to be protected, on the plunger. If thepainting, or typewriter 99, stealing of which is to be prevented, islifted away from or otf plunger 92, spring 98 will force the plungerupwardly, and plate 22 will be released so that plate 12 will rotateunder actuation of spring 24, setting oif the alarm as above described.

Thus it will be seen that I have provided a very simple inexpensivedevice for operating an alarm in case of fire or burglary, or opening ascupper or drain in case of high water, etc.

Having thus described my invention, what I claim is: 1. A control devicecomprising: a casing, a cap for closing one end of said casing, a pairof electrical terminals projecting into said casing, a plate bridgingsaid terminals to close an electric circuit therethrough, 1

means having a portion thereof on the inside of said casing forreleasably holding said plate in inoperative position,

operable means on the outside of said casing and cooperating with saidholding means for releasing said holding means, and

means operable, upon release of said plate, to move said plate to itsoperative bridging position.

2. A control device as claimed in claim 1, wherein said holding meanscomprises:

a pin engageable in a recess in said plate,

a spring constantly urging said pin to released position,

and

means for normally retaining said pin in said recess, the

last-named means being operative to release said pin when saidexternally-operable means is actuated.

3. A control device as claimed in claim 2, wherein said holding meansalso includes a detent on the inside of said cap, and

said plate has a hole in it which when in registry with said detentcauses said plate to be released from said cap.

4. A control device as claimed in claim 3, wherein means is provided forholding said cap stationary in said casing relative to said plate.

5. A control device as claimed in claim 1, wherein the means for movingsaid plate to bridging position comprises:

a coil spring secured at one end to said plate and at its opposite endto said casing.

6. A control device as claimed in claim 5, wherein the means forreleasably holding said plane in inoperative position comprises:

a detent on said cap, and

said plate has a hole in it which in the inoperative position of saidplate is out of registry with said detent and which when in registrywith said detent releases said plate and permits movement of said plateto operative position.

7. A control device as claimed in claim 6, wherein said holding meanscomprises a pin engaging a recess in said plate, and a spring constantlyurging said pin to released position, and

said operable means preventing movement of said pin to released positionuntil ambient conditions exceed a predetermined limit.

8. A control device as claimed in claim 7, wherein the first-namedspring rotates said plate and also moves said plate rectilinearly tooperative position upon release of said plate from said cap.

References Cited UNITED STATES PATENTS 2,955,180 10/1960 Denton 337-410ROBERT S. MACON, Primary Examiner M. GINSBURG, Assistant Examiner U.S.c1. X.R.

